Product developments in chemical, pharmaceutical, dietetic, cosmetic, and food industries has led to the creation of new packages consisting of several contents. The contents of the packages are not to be mixed until the moment of their utilization. The contents can be packaged in separate containers to prevent the contents from interacting or mixing prior to their determined use. A partitioning between the containers can further ensure separate storage of the contents before their utilization.
In the case of pharmaceutical products it is beneficial to keep substances, such as chemicals, separated prior to use to prevent physicochemical reactions caused by mixing of the substances. Similarly, in the case of food products, such as injectable pastry products, it is beneficial to keep the food substance separated prior to use to preserve the distinction of aromas and taste. Also, in the case of industrial supplies, such as cream and gels or in the field of manufacture of certain hardeners of fast-acting glues, it is beneficial to keep the substances separate prior to use.
In the case of food products, in order to avoid mixing before consumption, the majority of multi-layer food products present on the market today, use a concept that is based on layering, resulting from the difference of viscosity and density between each product. However, layering does not guarantee that mixing will not occur, notably during transportation which, due to poorly damped shocks, may cause instantaneous and unintended mixing of the two substances, thus, making the product difficult to market.
One solution to premature mixing of substances is based on a packaging concept called double packaging. Such a device is described in French Patents 2633250 and 2783804, which propose a packaging made with a homogeneous and tight block superimposing two compartments, one of the containers having an operculated orifice on its outside surface which is pierced using an external item, outside of the packaging, the said item of perforation item also serving to perforate the separation between the two compartments in order to mix the two contents.
However, one disadvantage of this device is that the material used as a partition wall between the two compartments upon removal does not completely expose the two superimposed compartments. As a result, the substances within each compartment may not be adequately mixed. Furthermore, the devices may not sufficiently protect the material or the partition wall used to separate the different compartments, for example, during routine handling of the device.
Another solution of the prior art described in French Patent 2507573 consists of a two compartmental containers. The two compartments are separated by a partition wall that can be perforated by a perforating device placed inside the container. One disadvantage of this device is that it is handled with the aid of a straw, which provides the perforation of the partition wall between the two compartments and the mixing of the contents of the two compartments. The partition wall between the two compartments comprises aluminum sheets which do not permit a complete opening with the straw. In such cases, the content flow from the upper compartment may be incomplete and not allow proper mixing.
Another device of the prior art described in European Patent 0232814 describes a two compartment container, the cover of which has a perforating device. The deformation of the container permits perforation of the partition and mixing of two substances stored separately in each of the two compartments. However, the container is opened from the top to tear a separation wall, an action which does not always result in the removal the torn separation wall of the container.
Another device described in European Patent 0173547 proposes a container composed of three parts namely a first principal container filled with a first substance, a second container located in the first compartment and closing it, and being supported on the edge of its opening, and a cover assuring sealing of the second container and perforation of the bottom of the second compartment. However, the two compartment system has one disadvantage of perforating the bottom of a compartment and not a cover, which requires additional action from the user.
U.S. Pat. No. 3,695,478 and European Patent 0461693 describe a stopper for cartridges which is subsequently clipped on a needle of a hypodermic syringe. A rubber or elastomer stopper is employed to allow for closure after the stopper is pierced, thus allowing for reuse of the stopper. However, this type of stopper does not adequately permit a complete and definitive opening of the cartridge.
Another device described in British Patent 1,192817 proposes a packaging capsule for pre-dosed dental amalgam, which has two compartments, containing two substances, which are intended to be mixed only at a time of the use, and which are separated by a membrane. The membrane opens when the capsule is accelerated above a threshold value, for example, when the capsule is placed in an amalgamator. For example, the amalgamator can spin the capsule around to accelerate the substances and push them through the membrane. However, the membrane, which has a predetermined form generally only stays open during the acceleration and closes afterward. In such regard, the opening does not completely remain open after exposure of some of the substances.
U.S. Pat. No. 4,182,447 discloses a method of shaking a capsule to induce a rupture of a membrane separating the substances. A plunger placed in one of the compartments that is free to move in the compartment causes a rupture of the membrane responsive to the shaking movement.
U.S. Pat. No. 4,863,017 describes a double packaging for dental amalgam. IA membrane having a shape of a funnel with a small hole at its lower part, can retain mercury without flow due to the physical properties of the membrane. Under a centrifuge force, the mercury pushes through the small hole to be mixed with the second compound packed in this double packaging. The opening remains opened during the centrifugal process.
U.S. Pat. Nos. 4,776,455, 3,730,337, and 3,077,262 disclose an inner packaged container, such as a sachet, where two folds of the sachet are sealed in the middle of the whole package. This provides two compartments but without a partition wall. A pressure on one compartment can break the sealing between the two compartments to induce a mixing of the substances within the two compartments.
U.S. Pat. No. 4,856,651 describes a thermal pack containing an inside sachet. In each compartment there is a product which is put in contact with the other only by squeezing the pouch manually.
U.S. Pat. No. 5,476,175 describes a wrapping pouch having two compartments, one compartment contains an object to be wrapped, the second compartments contains a gas. The second compartment provides a protective surrounding to the first compartment. The partitioning between the two compartments remains intact to protect the object. The partitioning is not intended to be broken sand helps avoid shocks during transportation.